ER (, "the watchful"):

1. First son of Judah by Shuah the Canaanite (Gen. xxxviii. 3; Num. xxvi. 19). He died soon after marrying Tamar, because he "was wicked in the sight of the Lord" (Gen. xxxviii. 7). What his sin was is explained in Bereshit R. lxxxv. 4.